JPH062797B2 - Epoxy resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an epoxy resin composition, and more particularly to an epoxy resin composition having good imprintability.

Conventional technology and problems to be solved by the invention Epoxy resin and an epoxy resin composition in which an inorganic filler and the like are mixed are generally more moldable, adhesive, electrical property, mechanical than other thermosetting resins. Because of its excellent properties and moisture resistance, it has been widely used as various molding materials, powder coating materials, electrical insulating materials, and the like, and has recently been attracting attention as a semiconductor sealing material.

However, the conventional epoxy resin composition is cracked at the time of curing, and therefore, molding, the appearance of the coated surface is impaired, and many of them cause defects in elements and devices such as semiconductors, so as to solve this problem. The inventors previously proposed an epoxy resin composition having excellent crack resistance by adding a block copolymer composed of an aromatic polymer and an organopolysiloxane to a curable epoxy resin ( Japanese Unexamined Patent Publication (Kokai) No. 58-21417) has further excellent moldability, such as excellent crack resistance, low expansion coefficient, high glass transition point, and therefore small amount of deformation during molding, and flexural strength and bending. There has been a demand for an epoxy resin composition that does not impair properties such as mechanical strength such as elastic modulus.

Further, an epoxy resin composition containing a block copolymer composed of an aromatic polymer and an organopolysiloxane,
There was a drawback that the marking property of the molding surface was poor and it was difficult to print the marking ink.

The present invention has been made in view of the above circumstances, flexural strength, without impairing the mechanical strength typified by flexural modulus, yet low expansion coefficient, high glass transition point, excellent crack resistance, and An object of the present invention is to provide an epoxy resin composition capable of imprinting on a molding surface.

Means and Actions for Solving the Problems In order to achieve the above-mentioned object, the present inventors have added a curable epoxy resin and a curing agent to an epoxy resin composition containing an inorganic filler, and further imprintability, As a result of diligent study on the block copolymer component which brings about an excellent effect on crack resistance, an alkenyl group-containing epoxy resin and the following formula (1) (In the formula, R is a hydrogen atom or a methyl group, and a,
b, c and d are a ≧ 1, b ≧ 0, c ≧ 0 and d ≧ 0, respectively.
Is shown, and b + c ≧ 1. In addition, the content ratio of the phenyl group to the total of the methyl group and the phenyl group is 4 to 15
Mol%, and the number of hydrogen atoms directly bonded to silicon atoms in one molecule is at least 2. [1], which is obtained by an addition reaction with an organopolysiloxane in which the number of silicon atoms in one molecule is 70 to 300
And in the alkenyl group-containing epoxy resin and the formula (1),
Copolymer [II] / copolymer [I] = 0.3 with copolymer [II] obtained by addition reaction with organopolysiloxane having 20 to 30 silicon atoms in one molecule.
It was found that the organopolysiloxane copolymer mixture containing phenyl groups in the side chains, which had been mixed in a weight ratio of ˜0.6, had excellent properties.

That is, generally, when an organopolysiloxane having a molecular weight of 3000 to 7000 is used to obtain a copolymer with an alkenyl group-containing epoxy resin, the copolymer has poor compatibility with an epoxy resin matrix and easily undergoes phase separation. The surface of the molded product of the epoxy resin containing the polysiloxane copolymer had a defect that the imprintability was not good. On the other hand, by introducing a phenyl group into the side chain of the organopolysiloxane molecule, the imprintability is improved and
The copolymer mixture obtained by mixing the copolymer of the long-chain organopolysiloxane copolymer of (1) and the short-chain organopolysiloxane in a specific ratio can be uniformly dispersed in the curable epoxy resin. When the polymer mixture is blended with the epoxy resin composition, not only the glass transition point is not lowered, but also an epoxy resin composition having a low expansion coefficient is obtained, and the copolymer mixture is the same as the curable epoxy resin. Or, because it contains a similar epoxy resin segment, it has a high affinity for the curable epoxy resin and therefore enables micro-dispersion, dramatically improving the crack resistance, and further, the aluminum electrode due to the stress generated during the heat cycle test. The inventors have found that an epoxy resin composition with a small amount of deformation can be obtained, and completed the present invention.

Therefore, the present invention provides an epoxy resin composition containing an epoxy resin, a curing agent, and an inorganic filler, in which an alkenyl group-containing epoxy resin and an organopolysiloxane having a phenyl group in the side chain represented by the above formula (1) are used. A long-chain copolymer [I] and a short-chain copolymer [II] obtained by an addition reaction with a mixture of copolymers in a weight ratio of [II] / [I] = 0.3 to 0.6 Provided is an epoxy resin composition comprising a blended mixture.

Hereinafter, the present invention will be described in more detail.

The epoxy resin constituting the composition of the present invention contains 2 epoxy compounds per molecule.
It is an epoxy resin having at least one epoxy group, and this epoxy resin is not particularly limited in its molecular structure, molecular weight, etc., as long as it can be cured by various curing agents as described below, and it has been conventionally known. Various compounds can be used, for example, an epoxy resin synthesized from epichlorohydrin and various novolac resins including bisphenol, an alicyclic epoxy resin, or an epoxy compound containing a halogen atom such as chlorine or bromine atom. Resin, epoxidized triphenol methane, etc. can be mentioned.

Here, the epoxy resin is not necessarily limited to only one type when used, and two or more types may be mixed.

In using the epoxy resin, a monoepoxy compound may be appropriately used in combination, and examples of the monoepoxy compound include styrene oxide, cyclohexene oxide, propylene oxide, methylglycidin ether, ethylglycidin ether, and phenylglycidin ether. , Allyl glycidin ether, octylene oxide, dodecene oxide and the like.

As the curing agent, amine curing agents represented by diaminodiphenylmethane, diaminodiphenyl sulfone, metaphenylenediamine, etc., acid anhydride curing agents such as phthalic anhydride, pyromellitic dianhydride, and benzophenone tetracarboxylic anhydride. , Or phenol novolac,
Phenol novolac curing agents having two or more hydroxyl groups in one molecule such as cresol novolac are exemplified.

The copolymer blended in the epoxy resin composition of the present invention,
Alkenyl group-containing epoxy resin and the following formula (1) (In the formula, R is a hydrogen atom or a methyl group, and a,
b, c and d are a ≧ 1, b ≧ 0, c ≧ 0 and d ≧ 0, respectively.
Is shown, and b + c ≧ 1. In addition, the content ratio of the phenyl group to the total of the methyl group and the phenyl group is 4 to 15
Mol%, and the number of hydrogen atoms directly bonded to silicon atoms in one molecule is at least 2. [1], which is obtained by an addition reaction with an organopolysiloxane in which the number of silicon atoms in one molecule is 70 to 300
And in the alkenyl group-containing epoxy resin and the formula (1),
A copolymer obtained by an addition reaction with an organopolysiloxane having 20 to 30 silicon atoms in one molecule [I
And [I] in a weight ratio of [II] / [I] = 0.3 to 0.6.

Examples of the alkenyl group-containing epoxy resin that is reacted with the organopolysiloxane include compounds represented by the following formulas.

formula formula formula formula (However, in the above A042-A045 formula, p and q are usually 1
It is an integer of ≦ p ≦ 20 and 1 ≦ q ≦ 10. ) It should be noted that these alkenyl group-containing epoxy resins are obtained by a usual synthetic method, for example, epoxidizing an alkenyl group-containing phenol resin with epichlorohydrin, partially reacting various known epoxy resins with 2-allylphenol, etc. Can be easily obtained.

On the other hand, the organopolysiloxane of the above formula (1) used in the present invention is supposed to have at least two hydrogen atoms directly bonded to a silicon atom in one molecule. Those having a Si-H group are preferable, and examples thereof include the following formulas.

[Long-chain organopolysiloxane]

formula formula formula [Short-chain organopolysiloxane] Formula formula Here, the long-chain organopolysiloxane of the formula (1) has the number of silicon atoms in one molecule (hereinafter referred to as “degree of polymerization”).
Is required to be in the range of 70 to 300, preferably 100 to 150. If the degree of polymerization is less than 50, sufficient flexibility cannot be imparted and a high glass transition point cannot be obtained. When it exceeds 300, it is extremely difficult to obtain a copolymer from the viewpoint of synthetic technology. Further, the degree of polymerization of the short chain organopolysiloxane is 20 to 30, preferably 2
It is necessary to be in the range of 3 to 26, and if it deviates from this range, the crack resistance of the obtained epoxy resin composition will deteriorate. Generally, when the epoxy resin composition has the same silicone content, the higher the degree of polymerization, the better the glass transition point, but the crack resistance or the adhesion to the device tends to decrease. The crack resistance and the tendency of the decrease in the adhesion to the element are effectively reduced by using the above-mentioned two kinds of organopolysiloxane copolymers of long chain and short chain in a specific ratio as the organopolysiloxane. Can be improved.

As the copolymer of the present invention, an alkenyl group-containing epoxy resin and a long-chain or short-chain organopolysiloxane of the formula (1) are respectively subjected to an addition reaction, and a copolymer obtained by mixing two kinds of copolymers obtained Use a coalescing mixture. When such a copolymer mixture is blended with an epoxy resin composition, the copolymer mixture is incompatible with the epoxy resin matrix and constitutes a fine sea-island structure, so that the crack resistance of the epoxy resin composition is improved. In addition, the amount of deformation during molding is reduced.

Furthermore, the mixing ratio [II] / [I] of the above-mentioned copolymers I and II when obtaining the copolymer mixture is 0.3 by weight.
It is necessary to set it to ˜0.6, preferably 0.4 to 0.5.
Mixing ratio [II] of the above organopolysiloxane copolymer
If / [I] is less than 0.3, the dispersibility of the copolymer in the epoxy resin matrix will be poor, and the heat resistance and crack resistance of the epoxy resin composition will be inadequate. Since it is easily dissolved in the epoxy resin, the glass transition point of the epoxy resin composition is lowered and the crack resistance becomes poor.

In general, an epoxy resin composition containing an organopolysiloxane copolymer tends to have poor imprintability on the molding surface. The reason for the lowering of the imprintability is due to the methyl group of the organopolysiloxane, and by introducing a phenyl group instead of the methyl group, the imprintability of the molding surface becomes good.

The content ratio of the phenyl group is 4 in mol% of the phenyl group based on the total of the methyl group and the phenyl group in the above formula (1).
It is necessary to be in the range of 15 to 15 mol%, and if it is less than 4 mol%, the imprintability is insufficient, and if it exceeds 15 mol%, the imprintability is good, but the organopolysiloxane copolymer is in the epoxy resin matrix. It becomes difficult to form a good sea-island structure, and the crack resistance of the epoxy resin composition deteriorates. The preferred phenyl group content in this organopolysiloxane is 10 to 15 mol%.

Further, these copolymers can be obtained by mixing the above alkenyl group-containing epoxy resin and organopolysiloxane at room temperature or high temperature to carry out an addition reaction. At the time of this reaction, both are mixed in a uniform or nearly uniform state. Therefore, it is desirable to use a solvent such as methyl isobutyl ketone, toluene, dioxane, and methyl cellosolve. To further accelerate the reaction, water, butanol, isopropyl alcohol, alcohols such as ethanol, or phenol, or It is preferable to use a known platinum group metal-based catalyst for the addition reaction in the reaction,
Examples of the platinum group metal-based addition reaction catalyst include platinum-based, palladium-based, and rhodium-based catalysts, and the platinum-based catalyst is preferable. As the platinum-based catalyst, solid platinum is supported on a carrier such as platinum black, alumina or silica, chloroplatinic acid, alcohol-modified chloroplatinic acid, a complex of chloroplatinic acid and olefin, a complex of platinum and vinylsiloxane. Is exemplified. These platinum group metal-based addition reaction catalysts are preferably added to the alkenyl group-containing epoxy resin in a proportion of 0.5 to 500 ppm, especially 2 to 200 ppm in terms of platinum group metal.

Furthermore, the above copolymer is preferably in order to obtain an epoxy resin composition excellent in crack resistance and adhesiveness with an element, which is not compatible with the epoxy resin matrix and has a fine sea-island structure. Therefore, the functional group equivalent of the long-chain organopolysiloxane of formula (1) or the short-chain organopolysiloxane, that is, ≡Si—H group equivalent is (X), and the molecular weight of the alkenyl group-containing epoxy resin is (Y). If 1.
It is desirable to react in the range of 0 <(X) / (Y) <25.

When the total amount of the above organopolysiloxane copolymer mixture in the epoxy resin composition is less than 1 part by weight based on 100 parts by weight of the total amount of the epoxy resin and the curing agent, the glass transition point of the epoxy resin composition is improved. In some cases, the effects of improving crack resistance, suppressing movement of aluminum wiring, etc. may be insufficient, and when it exceeds 100 parts by weight, the mechanical strength of the epoxy resin composition may tend to decrease. ˜100 parts by weight, particularly preferably 2 to 60 parts by weight.

The epoxy resin composition of the present invention may contain an inorganic filler, if necessary.

In this case, the inorganic filler is blended in a usual amount, and there is no limitation on the type of the inorganic filler, a single use or a combination of a plurality of types, and it is appropriately selected according to the application of the epoxy resin composition, for example, One or more selected from natural silica such as crystalline silica and amorphous silica, synthetic high-purity silica, synthetic spherical silica, talc, mica, silicon nitride, boron nitride, and alumina can be used. .

The composition of the present invention may further contain various additives depending on the purpose, use, etc., if necessary. For example, waxes, releasing agents such as resin acids such as stearic acid and metal salts thereof, pigments such as carbon black, dyes, antioxidants, flame retardants, surface treatment agents (γ-glycidoxypropyltrimethoxysilane). Etc.) and other additives may be blended. In the composition of the present application, in order to further accelerate the curing reaction by the above-described curing agent, tributylamine, amines such as 1,8-diazabicycloundecene-7, and triphenylphosphine as a curing accelerator are included. It is desirable to use organic phosphines and imidazoles such as 2-phenylimidazole.

The composition of the present invention is prepared by uniformly stirring and mixing predetermined amounts of the above-mentioned components, and kneading with a kneader, roll, extruder or the like preheated to 70 to 95 ° C., cooling, and pulverizing. Obtainable. There is no particular limitation on the order of mixing the components.

INDUSTRIAL APPLICABILITY The epoxy resin composition of the present invention can be suitably used as a molding material and a powder coating material, as well as for sealing semiconductor devices such as ICs, LSIs, transistors, thyristors, and diodes, and for manufacturing printed circuit boards. Can also be used effectively.

The semiconductor device can be sealed by a conventionally used molding method, such as transfer molding, projection molding, or casting method.
In this case, the molding temperature of the epoxy resin composition is 150 to 1
80 ° C, post cure at 150-180 ° C, 2-16
It is preferable to carry out for an hour.

EFFECTS OF THE INVENTION As described above, the present invention provides an epoxy resin and a curing agent,
In addition to the inorganic filler, the flexural strength was improved by blending the copolymer mixture obtained by the addition reaction of the alkenyl group-containing epoxy resin and the specific long-chain or short-chain phenyl group-containing organopolysiloxane at a specific ratio. , Without lowering the mechanical strength such as bending elasticity, yet having a low expansion coefficient and a high glass transition point and excellent in crack resistance,
The molding surface has good imprintability, molding materials, powder coating materials,
Alternatively, an epoxy resin composition that is preferably used as a sealing material for semiconductors can be obtained.

Next, production examples of the copolymer used in the present invention will be shown by synthesis examples.

[Synthesis example]

In a normal four-necked flask equipped with a reflux condenser, a thermometer, a stirrer and a dropping funnel, the cresol novolac resin and allyl glycidyl ether were added and reacted, and then epichlorohydrin was further added to carry out the reaction. Epoxidized and alkenyl group-containing cresol novolac epoxy resin (allyl equivalent 150
0, epoxy equivalent 270, hydrolyzable chlorine 700ppm)
Got

Alkenyl group-containing cresol novolac epoxy resin 120 obtained by the above method was placed in the same four-necked flask as above.
g, methyl isobutyl ketone 100 g, toluene 200
g, 0.04 g of a 2-ethylhexanol-modified chloroplatinic acid solution having a platinum concentration of 2%, respectively, and subjected to azeotropic dehydration for 1 hour, and at a reflux temperature, 50 g of phenyl group-containing organopolysiloxane shown in Table 1 was added for a dropping time. In 30 minutes,
Further, after stirring at the same temperature for 4 hours to cause a reaction, the obtained contents are washed with water, and the solvent is distilled off under reduced pressure.
The reaction products (copolymers A to U) shown in Table 1 were obtained.

In Table 1-1, A to J are copolymer mixtures used in the present invention, and in Table 1-2, K to U are copolymers used as comparative products.

Phenyl group-containing organopolysiloxane [Here, a, b, c, d are as follows. ] Hereinafter, the present invention will be specifically described by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples. In the following examples, all parts are parts by weight.

[Examples and comparative examples]

54 parts of epoxidized cresol novolac resin having an epoxy equivalent of 200, 35 parts of a phenol novolac resin having a phenol equivalent of 110, and the first of the copolymers obtained in the synthesis examples.
16 parts of those shown in the table were mixed, and 10 parts of brominated epoxy novolac resin, 1.5 parts of γ-glycidoxypropyltrimethoxysilane, 1.5 parts of wax E, 1.0 part of carbon black, 0.8 parts of triphenylphosphine were added. The resulting blend was uniformly melt-mixed with a hot two-roll to prepare 21 kinds of epoxy resin compositions (Examples 1-10, Comparative Examples 1-1).
1) was produced.

For these epoxy resin compositions, the following (a) ~
Various tests of (f) were conducted.

(A) Spiral flow value Using a mold conforming to the EMMI standard, 175 ° C, 70
It was measured under the condition of Kg / cm ₂ .

(B) Mechanical strength (flexural strength and flexural modulus) According to JIS K6911, a 10 × 4 × 100 mm bending bar was molded under the conditions of 175 ° C., 70 kg / cm ₂ , and molding time of 2 minutes. It measured about what was post-cured for time.

(C) Glass transition temperature, expansion coefficient Using a test piece having a diameter of 4 mmφ × 15 mm, the value when the temperature was raised at a rate of 5 ° C./min was measured by a dilatometer.

(D) Crack resistance 9.0 x 4.5 x 0.5 mm silicon chip 14 PI
It is adhered to an N-IC frame (42 alloy), and the epoxy resin composition is molded thereon under molding conditions of 175 ° C. × 2 minutes,
After post-curing at 180 ° C for 4 hours, -196 ° C x
A heat cycle of 1 minute to 260 ° C. × 30 seconds was repeatedly added, and the resin crack occurrence rate after 200 cycles was measured.

(E) Imprintability Epomark (manufactured by Shin-Etsu Chemical Co., Ltd.) is printed on the molding surface of a test piece of 50 mmφ × 3 mm, then cured at 150 ° C. for 2 hours, and the printed surface is rubbed with gauze (100 g load). Thus, the number of times until the printing disappeared was measured.

◎ ・ ・ ・ Good for 50 times or more △ ・ ・ ・ Good for 50 to 20 times × ・ ・ ・ Disappearing after 20 times or less (F) Taping property A 20 mm wide cellophane tape is attached to a 50 mmφ × 3 mm test piece, and the molding surface is adhered to the cellophane tape. The force was measured.

From the results shown in Table 2, an epoxy resin composition prepared by blending the copolymer mixture obtained by the reaction of the alkenyl group-containing epoxy resin according to the present invention and the long-chain and short-chain organopolysiloxanes having phenyl groups on the side chains. Is a flexural strength as compared with an epoxy resin in which the copolymer mixture is not blended,
It can be seen that the mechanical strength such as flexural modulus is not impaired, the expansion coefficient is not more than the same, the glass transition temperature is high, the crack resistance is excellent, the imprintability and the taping property are good. It has been found that the present copolymer is suitable as a molding material, a powder coating material, or a semiconductor sealing material.

Front page continuation (72) Inventor Toshio Shiobara 2-13-1 Isobe, Annaka-shi, Gunma Shin-Etsu Chemical Co., Ltd. Silicon Electronic Materials Research Laboratory Research Officer Yoko Nakajima

Claims (1)

[Claims] 1. An epoxy resin composition containing an epoxy resin, a curing agent, and an inorganic filler, wherein the alkenyl group-containing epoxy resin and the formula (1) are used. (In the formula, R is a hydrogen atom or a methyl group, and a,
b, c and d are a ≧ 1, b ≧ 0, c ≧ 0 and d ≧ 0, respectively.
Is shown, and b + c ≧ 1. In addition, the content ratio of the phenyl group to the total of the methyl group and the phenyl group is 4 to 15
Mol%, and the number of hydrogen atoms directly bonded to silicon atoms in one molecule is at least 2. [1], which is obtained by an addition reaction with an organopolysiloxane in which the number of silicon atoms in one molecule is 70 to 300
And in the alkenyl group-containing epoxy resin and the formula (1),
A copolymer obtained by an addition reaction with an organopolysiloxane having 20 to 30 silicon atoms in one molecule [I
I] and copolymer [II] / copolymer [I] = 0.3 to 0.6
An epoxy resin composition comprising a copolymer mixture mixed in a weight ratio of 1.